1.What is depressed scar? A scar caused by a defect in the dermis and subcutaneous tissues of the skin, where the scar surface is significantly lower than the surrounding normal skin and the skin at the scar forms adhesions with the deeper tissues, thus forming a depressed deformity on the body surface. Acne, surgery, trauma, infection, chicken pox and smallpox are common causes of depressed keloid scars. In mild cases, only localized depressions are involved, while in severe cases, depressed deformity of the contour is caused. 2.What are the current treatments for depressed scarring? The current treatment methods for depressed scarring include grinding, laser, soft tissue injection filler and surgery. Dermabrasion is commonly used to treat superficial depressed facial scars, but it cannot correct the facial contour deformity caused by scarring, and it is also easy to form scarring and pigmentation if the grinding is too deep. High-energy pulsed CO2 laser and Er:YAG laser are mostly used to treat superficial depressed and atrophic scars, which can improve the skin softness and clinical appearance of the scar, but cannot improve the contour deformity caused by the scar, and there are complications such as permanent pigmentation. Soft tissue injectable fillers can improve the contour deformity to some extent, but they are less effective in improving the texture of the scar and require repeated, regular injections. Scar release alone will result in re-adhesion of the skin to the subcutaneous scar tissue and will not improve the contour deformity caused by the lack of subcutaneous tissue of the scar. Surgical treatments such as scar excision and suturing, skin grafting and flap transplantation undoubtedly increase the chance of trauma to the patient. If the tension in the operated area is too high, new scar will be formed, and the lack of local tissues will form a new deformity. 3.Benefits of autologous fat filler for depressed scar treatment Facial depressed scar on the one hand, there is a deformity of the contour, on the other hand, the color and texture of the scar is different from the normal skin, a treatment method is needed that can improve both aspects at the same time. Autologous fat filler for depressed keloid scars collects fat from the abdomen, thighs, etc., and after certain treatment, injects it into the cavity formed by subcutaneous separation of depressed keloid scars, which not only corrects the contour deformity caused by the lack of subcutaneous tissue amount, but also improves the texture of the scarred skin, and prevents the re-adhesion of the skin to the subcutaneous scar tissue. Autologous fat injection for depressed keloid scars is a minimally invasive and simple treatment method that does not produce new scars after surgery.